Study of the mechanism of intestinal absorption of folates will be approached by use of the clinical models of gluten sensitive enteropathy, tropical sprue, and chronic alcoholism. The luminal disappearance of two simultaneously administered synthetic folates, H3- pteroylmonoglutamate and C14-pteroylheptaglutamate, will be measured by the technique of jejunal perfusion and the results correlated with measurements of jejunal folate conjugase in mucosal biopsy specimens. The metabolism of C14-pteroylheptaglutamate will be studied in vitro in the rat using an isolated mucosal cell preparation, the everted gut sac, and by localization of intestinal folate conjugase by segment and mucosal fractionation in both the rat and monkey. The effect of alcoholism with folate deficiency upon processes of intestinal absorption of simple and conjugated folates will be further evaluated by intestinal perfusion studies in monkeys placed on dietary regimens in which folate and ethanol content are varied.